<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>程序员常用样式</title>
		<style>
		.mydiv{
			width: 300px;
			height: 300px;
			background-color: #FF0000;
			color: lawngreen;
			margin: 0 auto;
			text-align: center;
		}
		.uname{
			width: 420px;
			height: 35px;
			border-radius: 5px;
			/* border: 1px solid red; */
			border: 2px dotted black;
			background-color: azure;
		}
		</style>
	</head>
	<body>
		<h1>背景样式</h1>
		<div class="mydiv">今天天气不错</div>
		<input type="text" style="background-color: #FF0000;"/>
		<h1>边框样式</h1>
		用户名<input type="text" class="uname"/>
	</body>
</html>
